The batch culture of Azotobacter vinelandii on glucose under nitrogen-
fixing conditions, seeking oxygen limitation conditions, has been stud
ied in order to use it as a Biological Test System for the experimenta
l study of oxygen transfer enhancement methods in aerobic fermenters.
Overall kinetic parameters for exponential growth and for linear growt
h (under oxygen limitation) have been determined. It was noted an appr
eciable influence of the oxygen transfer rate on glucose and oxygen up
take, which seems to be due to alginate production, excreted as a nitr
ogenase protection mechanism.